1. Field of the Invention
The present invention generally relates to clamping devices for woodworking and, more particularly, is concerned with a bar clamp device for use in wood manufacturing having adjustable clamping attachment bodies which are adaptable for various clamping applications.
2. Description of the Prior Art
Numerous woodworking clamps have been described in the prior art. While these woodworking clamps may have been suitable for the purpose for which they were designed, they would not be suitable for the purposes of the present invention as heretofore described. Thus, it is desirable to provide a woodworking clamp useful in wood manufacturing which has removable attachments useable for various clamping applications.
The following are clamping devices used in the woodworking industry.
Hand screws, or wooden parallel clamps, are holding devices for wood, plastic, and many other materials. They can be used on finished surfaces without any protective wood strips. They are made in sizes ranging from an opening between jaws of about 2" to an opening between jaws of about 17". When using a hand screw, the center spindle is held in the left hand and the end spindle in the right hand. Then the hand screw can be opened or closed by twisting the handles in opposite directions.
Bar clamps or cabinet clamps of steel or aluminum are used primarily for edge-to-edge gluing, for clamping up large surfaces, and for assembling furniture. Common lengths are from 2' to 10'. One end is adjusted by a friction clutch or catch while the other end has a screw for applying pressure. When using bar clamps, the screw should be turned out completely. The friction clutch or catch is moved until the clamp is slightly wider than the total width of the stock to be clamped. The clamp is then tightened by turning the screw. When using bar clamps on finished stock, as in assembling furniture, the surface of the wood must be protected. Normally clamp pads or pieces of scrap stock are placed between the jaws and the wood.
Pipe clamps are similar to bar clamps. Instead of a metal bar, the screw and the friction clutch are mounted on plumbing pipe that is threaded at the ends.
Spring clamps are used for many kinds of clamping. They look like oversize clothespins. They are particularly good when tight pressure is all that is needed or when the clamp must be applied and removed quickly. Some have rubber-covered jaws to protect the workpiece. There is a heavy-duty type that has pivoting jaws made of stainless steel with double rows of serrated teeth along the pressure edge. Such jaws can hold parts at any angle so that miter joints and other odd-shaped pieces can be clamped together easily.
C-clamps, or carriage clamps, are made in a wide variety of sizes and shapes and are commonly used when gluing stock face to face. The maximum opening sizes vary from about 2" to 12". Some C-clamps are made with an extra deep throat which gives maximum working clearance. When clamping a finished surface with C-clamps, always use cauls to protect the surface.
Quick clamps, which do the work of heavy C-clamps, are similar to short bar clamps, and can be adjusted by sliding the head along the bar. An edge-clamp fixture works with a quick clamp to help solve a common and difficult problem: gluing strips of wood to the edges of plywood or solid wood. The quick clamp grasps the work, and the edge clamp applies pressure to the edge material.
Band clamps are made with a metal clamp and a band of steel or canvas. They are used primarily for clamping round or irregularly shaped sections such as furniture frames. Steel bands are best for round objects, while canvas bands are better for odd shapes.
Hinged clamps fasten to the underside of a bench and are easily swung out of the way when not in use. They can be used for many types of gluing and clamping operations.
The 3-way edging clamp allows the "right angle" screw to be centered or positioned above or below the center on various thicknesses of material.
Several different types of clamps and jigs are available for gluing up meter joints and frames. The miter-and-corner clamp is ideal for assembling frames. Once the two parts are clamped together, the corner can be trued up with a backsaw if it doesn't fit properly. Since the corner is open, any kind of metal fastener can be installed easily.
A miter clamp for use with a hand screw is made of pieces of hardwood. This clamping jig is used for assembling many different sizes of frames and the clamp applies uniform pressure to all four joints at the same time. It leaves the joints visible so that you can make sure they are straight and tight. Frame clamps for larger jobs are also available.
Consequently, as can be seen from a review of the prior art, a need exists for an improved clamp for woodworking which has adjustable wood holding attachments whereby the clamp can be adapted to be used for multiple applications.